1. Field of the Invention
The invention relates to thermoelectric cooling devices and, more particularly, to thermoelectric coolers for liquid containing vessels.
2. Description of the Prior Art
A variety of portable coolers for liquid containing vessels or jugs have been proposed. Some of the devices have been exceedingly expensive, heavy, and awkward due to expensive compressor units of the refrigeration systems utilized therein. A variety of liquid heating and/or cooling devices for specialized purposes have also been proposed. The state of the art for specialized thermoelectric liquid cooling devices is indicated in U.S. Pat. Nos. 3,808,825, 2,991,628, 3,712,072, 3,314,242, 3,398,337, 3,713,302 and 3,243,965. U.S. Pat. No. 3,310,953 discloses a portable thermoelectric refrigerator for beverage containers. That device includes a unitary structure having side walls which define an upper compartment which closely surrounds a beverage container and a lower compartment which contains an external heat exchanger, a fan and fan motor, and a thermoelectric module. A transverse wall dividing the two compartments incorporates a second heat exchanger, the upper surface of which directly contacts the bottom of the beverage container in the open top upper compartment. A vessel having an insulating lid and a dispenser having a draw tube extending through a hole in the insulating top to the bottom of the beverage container is provided. The device disclosed in U.S. Pat. No. 3,310,953 has numerous disadvantages. The open top upper compartment in which the beverage container is contained requires an insulating top which is unlikely to efficiently prevent loss of heat through the gap between the insulating side walls of the upper compartment and the beverage container top. A dispenser having a pump incorporated therein is utilized to draw beverage out of the beverage container. The pump must be manually activated to dispense the beverage. Extended portions of the external heat sink in the lower compartment form supporting legs for the entire thermoelectric refrigerator, and the outer walls of the lower compartment are substantially spaced from the sides of the external heat exchanger. Consequently, only a portion of the air moved by the electric fan moves through the fins of the external heat exchanger. The remaining portion of the air moved by the fan passes through the open space between the walls of the lower compartment and the heat exchanger. This results in inefficient cooling and excessive power consumption by the fan motor. The heat exchanger disposed in the opposite side of the thermoelectric module contacts only a portion of the bottom of the beverage container, resulting in inefficient transfer of heat from the beverage container to the external heat sink via the thermoelectric module. The external heat sink or exchanger is excessively large and unduly expensive.
Accordingly, it is an object of the invention to provide a portable, low-cost jug cooler which very efficiently insulates jugs or liquid containing vessels from loss of heat.
Another object of the invention is to provide a thermoelectric jug or vessel cooler which minimizes power consumption by an electric power source providing power to a fan motor and a thermoelectric module.
A further object of the invention is to provide a thermoelectric jug cooler which efficiently moves ambient air through the fins of a heat exchanger.
A still further object of the invention is to provide a thermoelectric jug cooler which provides efficient dispensing of liquid from a container without the necessity for actuating a pump.
A yet further object of the invention is to provide a thermoelectric jug or liquid vessel cooler which overcomes the shortcomings of the above prior art.
A further object of the invention is to provide a thermoelectric cooler which efficiently operates with an inexpensive, minimum sized external heat exchanger.